Technical Giardiniera mystery part.

[giardini]

It's been years since I removed my Giardi's timing chain cover, which I just did to replace the leaking crankshaft seal.
I probably did not investigate this strainer/hinged flap thingy back then. I realise now that the hinge pin was missing, and the flap was rattling around in the cavity. I don't see this part in any parts list or diagram.
My best guess is it's a very crude crankcase pressure one-way valve, so crude I doubt my guess.
The problem is, if I put it back together it will all but block the flow of oil when the time comes to refill the crankcase...
My thanks go to anyone who could shed a little light on this.

 

[giardini]

Hello ? I know that there's experience of the Giardi engine on this forum, is the upshot that no one's ever even SEEN this part ?
It looks factory made, the hinge is spot-welded to the strainer plate and the flap perfectly (machine-) rolled to a very tight radius...
So I'm wondering if everyone systematically ditched it as an inconvenience, or... what ?

 

[TGiardiniera]

I was looking a this very part yesterday. It's been bugging me since I last rebuilt the engine about a quarter of a century ago, I couldn't figure it out back then. I can confirm oil fills have been painfully slow since that last rebuild... No idea.

 

[giardini]

I was looking a this very part yesterday. It's been bugging me since I last rebuilt the engine about a quarter of a century ago, I couldn't figure it out back then. I can confirm oil fills have been painfully slow since that last rebuild... No idea.

Well, thanks for that, it was a bit weird not having any feedback at all. I, on my part can confirm that having the "flap" disabled seems to cause no
calamity whatsoever. Based on your observation I'll leave it out, and just keep the strainer in place (taking THAT out would of course dramatically
increase the chances of accidentally dropping, say a 10 mm nut, into the filler neck shortly thereafter...).

 

[Giardy driver]

Hi Giardini,
Just registered here after finding your post.
Earlier this evening I was filling the engine with oil again, at least I tried to.
Temperature is low at the moment (some 10 degr C), and the 20W50 is like syrup. It's going in awefully slow, probably going to take more than an hour.
Seeing your mystery part I now understand; thanks for posting it.
After the first bit drained, I also saw a small loose metal plate looking down the filler neck. I hope to get it out, now it seems to block the opening almost completely.

The flap itself might be the first step in preventing drops of oil flying up the filler neck.
Found this picture; 10 is called "movable partition"

 

[Giardy driver]

For sure there are 2 different gaskets, it will also influence filling-speed

 

[Giardy driver]

Last update: it is indeed the "mystery part" lying loose in the filler neck. Can't get it out, for now I will leave it in.
Luckily I was able to get out the pivot pin, that's the only part that could get through the strainer.

Oil went in with help of a vacuum pump on the dipstick opening

 

[giardini]

Hi Giardy driver, thanks for the info. I never noticed that my engine was slow to accept oil from the filler neck, but then the "movable partition"
was out of action like yours. Also, the gasket was "open" like the one on the left of your picture.
The new gasket I got from Ricambi is like the one on the right, which makes no sense at all, so I enlarged that part to allow the oil in.
I have no delusion about being smarter than the engineers who designed the thing, but the disadvantage here is just overwhelming !